Manufacture of lubricating oils from shale oil



Patented Feb. 19,1952 7 UNITED STATES MANUFACTURE OF LUBRICATING OILS FROM SHALE OIL Paul Woog, Paris, France, assignor to Compagnie Francaise de Rafiinage (Societe Anonyme),

Paris, France No Drawing. Application June 5, 1946, Serial No.

674,626. In France August22, 1941 Section 1, Public Law 690, August 8, 1946 Patent expires August 22, 1961 3 Claims. (Cl. 260-671) It is known that crude shale-oils contain a mixture of aliphatic, naphthenic and aromatic hydrocarbons which is characterised, in general, by a relatively high proportion of unsaturated hydrocarbons, of the order of to 60% and a 5 relatively low proportion of aromatic hydrocarbons. Furthermore, these oils contain moreor less complex phenols, more or less complex nitrogenous bases, sulphuretted compounds, and various other substances in a comparatively low propor- 10 tion relatively to the previously mentioned ones.

The unsaturated character of crude shale-oils, which is probably due to the cracking that accompanies the distillation of the schist,does not appear to have been sufficiently taken intocon- 5 sideration heretofore. The treatments which have hitherto been carried out on shale-oil are mainly: either distillation, or cracking, followed by refining in order to obtain engine fuelsrandm We lubricating oils; the treatments are preceded or accompanied by alkaline and acid washing which is .intended to remove the phenols and the bases The cracking treatment doesnot enable gasoil with a good ketene number, or good quality lubricating oil to be obtained.

The distillation treatment may produce: a comparatively low proportion of heavy spirit, burning oil, gas-oil, distillates for the manufacture of oils, and residues. Owing to the high percentage of unsaturated and to a considerable proportion of aromatic hydrocarbons, the gas-oils obtained have a low ketene number, and the losses in the refining of the distillates for oils are substantial (the unsaturated and the aromatic hydrocarbons being carried away by the ordinary refining agents).

I have discovered that the polymerization and/or the arylation of the unsaturated hydrocarbons enables novel and much more advantageous results to be obtained. For this purpose the oil, according to the cases, being freed or not of the bases and of all or part of the phenols and acids, it is necessary to make the unsaturated hydrocarbons react, either on themselves (by polymerization), or on the aromatic (or even naphthem'c) hydrocarbons contained in the oil, 5 or added to the oil. It is also possible to convert the unsaturated hydrocarbons into chemical derivatives which are easy to separate from the mass, as will be explained hereinafter.

In the fraction distilling between the limits of the gas-oil, the extraction of the unsaturated and of the aromatic hydrocarbons by polymerization and/or arylation increases the katenenumber, in particular when the percentageof remaining naphthenic' hydrocarbonsis comparatively low'.

On the other hand, the products of polymerisation or of arylation obtained are lubricating oils of high viscosity and having a viscosityindex which is sufficient for practical uses. 1 .7

' In the distillates for oil, the extraction of the unsaturated hydrocarbons leaves an oil of which the stability is increased and which can be refined by means of the usual refining agents, with comparatively low losses. Its viscosity index is also increased if the percentage of remaining naphthenic hydrocarbons is small enough. On the other hand, the polymerisation or the arylation products obtained are oils which are much more viscous than the residue.

The operations of polymerization and/or 'of arylation can be applied to any other fraction of the shale-oiLoand produce viscous oils.

Arylation can also be effected by adding to morebr less narrow fractions of shale-oil, from which certain products have been removed as hereinbefore stated, aromatic hydrocarbons such :as benzena'toluene, xylene and homologous substances, naphthalene and homologous substances,

anthracene, and heavier, synthetic aromatic product's, such'as diphenyl or dibenzyl and their homologues, or finally synthetic or natural oils which are rich in'aromatic nuclei such as those described in French Patent No. P. V. 458,994, filed on June 23, 1941, in the name of Compagnie Francaise de'Rafiinage. I I

Theresults obtained by the treatment of shaleoils claimed by me are characterized by a considerable increase in the yield of viscous oils. On the one hand, the yield by weight-is increased by the reduction of the losses in the refining of the oil distillates, in the usual refining operations, by

the conversion into oil of unsaturated products belonging not only to'the oil distillates, but to all the fractions of the shale-oil, and finally the possibility of adding to the initial shale-oil aromatic products from an external source, and of incorporating them in the finished oil. On the other hand, the lubricating oils obtained by the treatment claimed may be more viscous than those contained in the most viscous distillates of the initial shale-oil.

The products obtained from the first arylation "of the olefines with the aromatics and in particular with benzene or naphthalene, can be reacted again with a suitable proportion of dihalo-alkyl. This operation enables the viscosity of the polymers to be increased.

The catalysts used for these polymerisations arethose generally considered suitable for the reaction of Friedel and Crafts and in particular the halides of aluminum, of boron or of iron, an-

timony, tin. Catalysts mainly comprising phosphoric acids may also be used.

The elimination of phenols from the oil need not necessarily be carried out thoroughly. It

phates), or by the hydrolysis of halides. It is also possible to prepare heavy poly-alcohols by th fixing of' hypochlorous acid (or its homologues) and hydrolysis. The homologous oxides may be advantageous in order to maintaina high 5 of ethylene oxide can also be obtained by the resistance to the oxidation of the oils, either to alkaline treatment of the chlorohydrins.

leave in the oil subjected to reaction, or to in- The treatment claimed hereinbefore for shalecorporate in the polymerization product obtained, oils can also be applied to certain fractions of a small quantity of the phenols of the original oil. the oil of distillation of lignite, which is rela- The heavy phenols are recommended forengine tively rich in unsaturated hydrocarbons.

oils owing to their comparatively low volatility. The process of treatment, according to the in- Consequently, it may be recommended for cervention, of shale-oils, can be illustrated by the tain shale-oils to iractionate the oil in more or following table, which is given by way of example, less narrow fractions before reaction and even and which indicates the various operations to before dephenolating. The dephenolating need 175 which the oil is subjected and which is followed not be carried out thoroughly in the fractions by a small numerical table which also gives, by which actually contain phenols which have the way of example, the characteristics of two fracdesired characteristics and which it is desired to tions of oil obtained. retain in the oil.

On the other hand, the fractionating of shale- Treatment oil before po yme o arylation y P A. Dephenolating.--The oils are washed 3 u t t i i y mea s f th times with about 10% of soda. Stir. Decant. Same Operations, results which are istinctly bet- Separate the phenolic lye. These alkaline washter than those which are obtained without prior ings are followed by a washing with water.

fractionation, in particular as regards the vis- 5 B. Polymerization-To the dephenolated oil 3 indeX and chiefly when the fractions conadd 10% of anhydrous aluminium chloride and taming olefines having unbranched or slightly stir for 48 hours at a temperature of 60 C. branched chains of 8 to 18 atoms of carbon are C. Treatment.The tars formed are allowed comparatively poor in aromatic substances. to settle, then the liquid remaining above is de- It is also possible to effect the polymerization 3Q canted. This liquid is washed: (1) with water or the arylation operations after fixing halogens containing of hydrochloric acid; (2) with or halogen acids on the unsaturated hydrocarwater; (3) with water alkalised with soda. bons, or halogens on the saturated hydrocarbons, D. Distillation-The liquid is distilled up to this latter substitution increasing the yield of a temperature of 200 C. at a pressure of 6 mm. oil. 5 of mercury.

Crude Gas Oil Lubricating oil obtained Viscosity in Yield by centistokes weight No. of the Density Boiling Density Viscosity relatively fraction l5/4C. point 15/4O. index to initial at 30 100 fljf p 1 0.864 2os-'2s2 0. 9406 50s 153 15.4 -14 18.4 2 0.880 252-323 0.9401 638 201 19.3v +19 16.5

The fixing of hydrochloric acid is particularly The above treatments as a whole which can advantageous as regards the cost of production 50 be applied, separately or in combination, to shalewhen this substance is obtained in the anhydrous oils to make them into lubricating oils and other state as a by-product of a condensation of aryl industrial petroleum products, include in particudichloride on the aromatic substances. lar the reacting of shale-oil with a suitable quan- When these halogen derivatives are formed, tity of dihalo-alkyl, but this operation is only polymerization or arylation can be obtained, not considered in the foregoing as the complement of only with the catalysts already referred to, but a prior arylation, for the purpose of which arcwith alkaline catalysts or alkaline alcoholates, matic substances such as benzene or naphthasuch as sodium ethylate. The use of alkaline lene or the like, were added to the oil. alcoholates enables 0R groups (B, being an or- Within the scope of the invention, it is also ganic radical) to be fixed on the molecules and, possible to proceed in a reverse manner, that is in the case of oil manufacture, the unctuousness to say react shale-oil with a dihalo-alkyl, withof the lubricants obtained to be increased. If the out any prior addition, I have, in fact, discovered operations are carried out on the halogen derivathat shale-oil naturally contains a sufficient protives in such a manner as to obtain chlorinated portion of aromatic and possibly naphthenic hyoils, the unctuousness is also increased thereby. drocarbons to react with dihalo-alkyl.

By the (ac-polymerization of the halogen deriva- I have discovered, on the other hand, that this tives of the unsaturated hydrocarbons of shaleoperation can be efiected just as well on the total oil with fatty vegetable or animal halogen acids, oil as on a fraction, this being possible with or esters or alcohols, it is possible to obtain viscous 7 without the prior elimination of the bases and oils having a high viscosity index and of high thephenols by acid and alkalinewashing.

unctuosity.

It is also possible. to manufacture from the olefines of'shale-oilall the usual olefine derivatives and in particular monoand poly-alcohols,

Finally, the dihalo-alkyls, that is to saythe a-dihalo-aliphatic hydrocarbons may be replaced by other diha'lo-al'iphatic hydrocarbons, in-particular' o-halogen hydrocarbons, such as dieither by hydration (by hydrolysis of olefine sui- 76 chloro l-3 propane, dichloro-l-e-butane.

oil.

Eazample 500 grams of shale-oil, previously treated with hydrochloric acid and with caustic soda in order to eliminate, the bases and the phenols, are reacted with 100 grams of dichloro-ethane and 65 grams of anhydrous aluminum chloride. The mixture'is 'heated' for 4 hours at boiling point in a fiask provided with a reflux cooler; the temperature remains at 104l05 C.

The reaction is accompanied by the evolution of 20.14 grams of gaseou hydrochloric acid.

After hydrolysis and washing, the excess of dichloroethane is eliminated by distillation and 475 grams of raw treated oil are obtained, which represents a yield of 95 percent with respect to the oil involved.

The raw treated oil may be subjected to a distillation in vacuo in order to eliminate the relatively light fractions and to adjust the viscosity of the residual oil in accordancewith the following table, which particularly showsa good viscosity index.

175 C. at 20 mm. pressure, i. e. about 300 C. at atmospheric pressure.

"The consumption of catalyst can be lowered if use is made of the tar from a. first operation for catalysing one or more subsequent operations. I have discovered that this reuse is subject to several conditions:

1. Contrary to what might be expected, it is necessary for the fraction treated to be refined beforehand. Although the catalyst is capable of producing the refining effect, it is not advis able to allow this action to occur at the same time as the catalytic action. This prior refining is effected by the usual means, but preferably with dilute acid.

Furthermore, the treatment with earth, whether it forms the sole treatment or whether it follows the refining with acid, always has the effect of making the tars more flexible and more homogeneous, which contributes to maketheir re-use possible.

2. For the tar to remain utilizable, that is to say to retain a non-granular structure, it is necessary to adjust very accurately the stirring as a function of the temperature and of the-duration of the reaction. There is an optimum adjustment for each operation, according to whether use is made of tar from 1, 2 or 1; previous operations.

30 I have finally discovered, on the one hand, that the treatment of the non-oily distillates could further produce an appreciable yield of oil, and on the other hand that it is advantageous to prepare the catalyst, which is intended to act Viscosity of 7 Proportion of res1dual Proportion of oil relatively toig ggg g Temperature oster burst Year raw "sated Raw Shale-oil At treated oil involved 35 C Percent Percent Percent v 10 V 7 u ll 89 84. 6 34. 6 l 4. 95 96.3 7 l7. 6 82. 78. 5 46. 33 5. 9 103 7 27 73 69. 5 87. 05 8. 66 93' 7 47 53 50.5 44 7 52 48 45.6 132 I The present patent involves moreover improved methods relating to the application of the general process above described and which are intended to increase further the yield of viscous oil and decrease the consumption of catalyst.

In the first place,-I have discovered that the treatment of theparaifin fractions of the crude oil does not produce any substantial increase in viscous oil, that it is therefore advantageous to remove these fractions prior to any treatment, and that it is thus possible to dispense with any deparaflining subsequent to the treatment, while obtaining oils having a suitable freezing point. This result is obtained by eliminating the heavy fractions of the oil, this elimination being more or less thorough according to whether a more or less low freezing point is desired for the finished With Autun shale oil, for instance, it has been found that it is necessary to reduce the oil to about 50% in order to obtain a freezing point of about 0., which in general is not sufficiently low for a lubricant. On the other hand, by only retaining about 37% of the oil, the freezing point is lowered to -10 0., this result being obtained without sacrificing in the slightest degree the increase of yield of viscous oil. This reduction amounts to fractionating the distillate at on the crude oil, by starting to treat-the nonoily distillates with said catalyst. The treatment of the distillates may increase by about 30 to the yield of an operation or of the successive operations of treatment with tars.

On the other hand, the preparation of the catalyst by means of the distillates may enable the yield to be doubled, even including in said yield the gain obtained bytreatment of the distillates. Q

An example, which is intended to make the invention clearly understood, is given hereinafter,

vention to the numerical data chosen to illustrate the process.

An Autun shale oil is fractionated to 37.5% Refining is eifected three times with 2% of 10% hydrochloric acid at room temperature, the tars being separated out after each operation. The product is washed, then neutralized three times with 2% of 10% caustic soda. Decant, then after washing and further decantation, treat at a temperature of C. with 5% of dried Aktisil earth. The necessary distillate for starting is obtained by treating a first charge in a reaction vessel holding 600 litres with a jacket for steam heating. The operation is effected at C. in the presence without its being my intention to limit the inor of AlCla; the duration or the reaction is 2hours. l

The tars from this first operation serve .for catalyzing a second operation at 100 C., the duration of which is 3 hours. The tars from this second operation serve for catalyzing a third operation at 100 C., the duration of which is 2 9 5 Stirring is adjusted each time to the optimum speed which is'predetermined by tests, in such a manner that the tars have a dry consistency after "the second operation, and a granular consistency after the third operation (or after the last operation, if there are more than three).

' The oily layer of each of the three operations is distilled. The three distillates, which represent about 65% of the total'o'f the three charges, are not sufdciently viscous to possess lubricating properties and are mixed together. These distillates are subjected "to a treatment with fresh aluminum 'chloride,'the quantity of which is equal to 10% of the first charge. The operation is efiected at 80 0., for twohours. This operation produces an increase in the yield of visc'ous oil of about 7 to 10% relatively to the total of the three charges. The tars obtained by this operation serve for three fresh operations on crude oil in identical conditions to those hereinbefore specified. The mixed distillates of these three fresh operations serve for preparing with fresh aluminum chloride a fresh catalyst for three other operations on crude oil, and so forth. 'The balance sheet of the yield works out as follows relatively to the crude oil:

Per cent Oil of viscosity 64 centistokes at 50 C 35 Oil of viscosity 45 centistokes at 50 C 8 Lamp oil 16 Gas-oil 30 Losses in refining 11 The figure or three operations on crude oil per cycle is in no way limitative, this figure having been chosen only for the convenience of the explanation. I have even discovered that it is possible to recycle the distillate a second time and that, although the yield of oil from this second operation is not considerable, said operation produces on the other hand, interesting products.

The spirit of the invention is not altered by converting the process hereinbefore described into a continuous or a semi-continuous process.

I claim:

1. In a process of produce a high grade lubricant therefrom, the steps of fractionating said crude shale oil to remove parafiin fractions therefrom, adding aroinatic hydrocarbons to the residual portion of said oil, and then heating the oil in the presence of'a -Friedel and Crafts catalyst to simultaneously polymerize and arylate unsaturated constituents of said oil to convert them into compounds having improved lubricating properties.

treating crude shale oil to 2. In a process of treating crude shale oil to produce a high grade lubricant therefrom, the steps'of treating the crude shale oil with hydrochloric acid to cause said acid to react with unsaturated constituents of said crude oil, simultaneously polymerizing and arylating the so treated oil in the presence of a Friedel and Crafts catalyst, mixing an alkyl dichloride with the polymerized and arylated oil, condensing said dichloride with aromatic constituents of said 011 in the presence of a Friedel and Crafts catalyst to produce compounds having improved lubricating properties and hydrochloric acid, and using the hydrochloric acid produced in said condensation step for treating the crudeoii in the first step above recited.

3. In a process of treating crude shale oil to produce a high grade of lubricant therefrom, the steps of fractionating said crude shale oil to remove parafiins therefrom, treating the fraction remaining after removal of said paraflins with hydrochloric acid to cause saidacid to react with unsaturated constituents of said oil, simultaneously polymerizing and arylating the so treated oil in the presence of a Friedel'and Crafts catalyst, mixing an alkyl dichloride with the polymerized and arylated oil, condensing said dichloride with aromatic constituents of said oil in the presence of a Friedel and Crafts catalyst to produce a product having improved lubricating properties and to produce hydrochloric acid, and using the hydrochloric acid produced in said condensation step'for treating the crude oil in the second step above recited.

PAUL WOOG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,811,243 Osmer June 23, 1931 1,954,972 Young Apr. 17, 1934 2,051,612 Loebel Aug. 18, 1936 2,080,701 Day 1 May 18, 1937 2,191,972 Ocon Feb. 27, 1940 2,204,609 Mikeska June 18, 1940 2,294,699 Steffen Sept. 1, 1942 2,318,625 Pier et a1 May 11, 1943 2,318,719 Schneider et a1. May 11, 1943 2,365,751 Drennan Dec. 26, 1944 2,398,908 Miller Apr. 23, 1946 2,422,443 Smith June 17, 1947 2,426,929 Greensfelder Sept. 2, 1947 FOREIGN PATENTS Number Country Date 713,149 France Aug. 10, 1931 690,525 Germany Apr. 29, 1940 OTHER REFERENCES Dunstan et al., The Science of Petroleum, vol. IV, Oxford University Press (1938), New York city, pages 3099 to 3103. 

1. IN A PROCESS OF TREATING CRUDE SHALE OIL TO PRODUCE A HIGH GRADE LUBRICANT THEREFROM, THE STEPS OF FRACTIONATING SAID CRUDE SHALE OIL TO REMOVE PARAFFIN FRACTIONS THEREFROM, ADDING AROMATIC HYDROCARBONS TO THE RESIDUAL PORTION OF SAID OIL, AND THEN HEATING THE OIL IN THE PRESENCE OF A FRIEDEL AND CRAFTS CATALYST TO SIMULTANEOUSLY POLYMERIZE AND ARYLATE UNSATURATED CONSTITUENTS OF SAID OIL TO CONVERT THEM INTO COMPOUNDS HAVING IMPROVED LUBRICATING PROPERTIES. 